Fuel tank removal advice

[FPW]

As title suggests I need advice on how to drop the fuel tanks and reinstall them. I also need to know step by step what process would be best to do so.

This weekend I'd like to check the tanks for crud and give them a good flush, I'm getting some issues with the carburetter and brake booster when the tank runs low(black smoke, hesitation, brake pedal stiffening up, high idle) so I'm thinking the tank is the problem.

thanks in advance.

[Beam318ti]

Here's what I have done in the past:

1. Jack up the car.
2. Drain the remaining fuel out of the tanks. What I have done to empty the tanks is to loosen one of the clamps on the hose that connect the two tanks and then drain the fuel through this hose as much as possible. I used a rather wide flattish rubbermaid container to catch most of the old fuel.
3. Lift the rear seat and open the cover that gives you access to the in-tank pump. Loosen and undo all the hoses and sensors that connect to the in-tank pump.
4. Remove other hoses connected to the fuel tanks. Most are held in place and tightened by clamps so the clamps can be cut if they are rusted.
5. Remove the 3 bolts that hold up each tank to the under-carriage. I believe they are held up by 13mm bolts.

Disclaimer---I may have forgotten a few other things as it has been awhile since I did this.

[Tom D]

if your only looking to flush then:

remove rubber hose connecting the two tanks and drain.
remove rear seat bottom
remove pre pump and sender
flush tank from the top where the sender goes
replace hose between tanks and flush second tank. (one year, not sure which, had axcess to the top of both tanks. one for the pump, one for the sender. maybe 82?)

[fullswing]

the factory manual has the procedure for this. (see link in my signature... right click, save as)

[joey79]

This pretty much covers it. When I removed my tanks, I disconnected the filler hose first, then siphoned the gas out via the filler opening. It's really a pretty easy job. As long as the tanks are empty, and all hoses/vent lines are disconnected, it's only 6 bolts holding the tanks up.

Here's what I have done in the past:

1. Jack up the car.
2. Drain the remaining fuel out of the tanks. What I have done to empty the tanks is to loosen one of the clamps on the hose that connect the two tanks and then drain the fuel through this hose as much as possible. I used a rather wide flattish rubbermaid container to catch most of the old fuel.
3. Lift the rear seat and open the cover that gives you access to the in-tank pump. Loosen and undo all the hoses and sensors that connect to the in-tank pump.
4. Remove other hoses connected to the fuel tanks. Most are held in place and tightened by clamps so the clamps can be cut if they are rusted.
5. Remove the 3 bolts that hold up each tank to the under-carriage. I believe they are held up by 13mm bolts.

Disclaimer---I may have forgotten a few other things as it has been awhile since I did this.

[Armydiver]

I would agree that the above covers it; just remember to watch the routing of the vent hose that runs above the tank and connects both. Also be careful not to break the T-connection that you will find after removing the cover under the back seat.

Take your time and take a picture of the tanks and hoses if you are concerned about remembering how to get them back together....

[erok320i]

I just did this two weeks ago. First, mine is a '79 and has an access hatch on both tanks. The other thing I would add is that you only have to actually remove the 4 forward most bolts(2 on each tank) and loosen the 2 in back(one on each) which have slots, not holes so the tank can tip down in front and slide off the tab in back. Helps to control the drop if there is fuel left in the tank. I left them connected, dropped them down in unison and slid them out together, but one at a time would be simpler.

[DrewDude320i]

I'd recommend changing the breather hoses while you're at it. If they're original, you can bet they're leaking.

[FPW]

ok. that helped plenty. for a moment i thought it involved dropping the subframe or driveshaft. I will have to read up on that manual.

Thanks for the input!

[tosiychuk]

I have a 2003 e46 330xi cant remove my tank because there is two lines in the way.

[Thecatmilton]

I have a 2003 e46 330xi cant remove my tank because there is two lines in the way.

Your in the wrong place. Go to the e46 section.

[tonyisok]

Those two lines are likely the E-brake cables

- - - Updated - - -

I think you are right on the e46 you likely need to disconnect d/s...and if you have to disconnect d/s then you need to drop exhaust and heat shield and those e-brake cables and maybe the subframe...and if you have to remove the subframe you will need to drop the rear diff and if you have to drop the rear diff then you have to separate the rear axles from the rear diff.